(a) Field of the Invention
The present invention relates to a mirror apparatus for an automobile, and more particularly it pertains to a mirror apparatus for an automobile which permits the driver to have a view of the blind area which may take place on that external side of the automobile located opposite to the location of the driver's seat.
(b) Description of the Prior Art
In a mirror of the above-mentioned type for use in a large-sized truck or other automobile wherein the driver's seat is located at a great distance from the ground, there exists a blind area on that external side of the automobile located opposite to the driver's seat, in spite of the fact that such an automobile is provided with a main side-mirror which is an independent ocular mirror and an under mirror which is another independent ocular mirror provided below the main ocular mirror. Because of such a known arrangement of mirrors, there frequently occurs that, when a person or a bicycle rider happens to be within such a blind area, the driver, from his position, is unable to recognize the presence of such a person or bicycle, and that in case the driver intends to turn in the direction of the blind area, the automobile drags or entangles the person or bicycle into the underside of the automobile due to the difference in the turning angle of the front wheels and rear wheels.
Referring now to FIG. 1, there is shown a part of the front side of an automobile such as truck having a known mirror apparatus. As shown, the mirror apparatus of, for example, a truck is comprised of a stay a to which are secured a main outside mirror b and an under mirror c. The main outside mirror b provides the driver a view as shown at B in FIG. 2. The view obtained from the under mirror c is shown at C in FIG. 2. The area W which is necessary for safety purposes contains a blind area Y. Because the under mirror has a curvature which is obtained by a radius of 100 mm to 120 mm, the image provided by the under mirror c is relatively small, and moreover this image has a large distortion and is poor in its visuality. Furthermore, the respective images provided by these two mirrors are sideways-inverted images, so that there is the problem that the driver has a difficulty in getting hold of the directional sense of the object. Another problem arises in that the under mirror c per se hinders the field of view. Also, the position of eyes, i.e. the position of the eyes of the driver at which the driver can have the best visibility of the image of an object varies with the physical size of the driver. In the known mirror apparatus, it has been difficult to adjust the position of the mirrors by a single person, and the driver most inconveniently is required to step down and get out of the driver's seat for the making of such an adjustment.
Because of these inconveniences, there has been developed a mirror apparatus presenting no such blind area as stated above and providing a good visibility of the image of an object without the accompaniment of the horizontal inversion of the image. Even in such a proposal, there still remains the problem that the adjustment of visual field is difficult. Also, in such a known combination mirror apparatus, the sunlight and the street lights impinge onto an ocular mirror as these lights are reflected by an objective mirror to be viewed by the driver as dazzling lights. Furthermore, in case an ocular mirror which is watched directly by the driver is arranged so that its mirror surfaces upwardly or to the sky, there will occur an instance such that, in case street lights and other lights are positioned above the ocular mirror, the light rays from these light sources will directly impinge onto the ocular mirror, so that unnecessary lights will be reflected into the driver's chamber by the ocular mirror. Such reflected lights, practically, constitute a hindrance, and in case these lights impinge onto the eyes of the driver, they will be dazzling light. Even if these unnecessary lights do not constitute a dazzling light, they could destroy the contrast of the image, so that there could occur an instance that the image which is reflected by the ocular mirror becomes dark and invisible. Such an occurrence will bring about a serious problem in the driving of automobiles.